<!doctype html>
<html>
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no" />
    <title>Your App</title>
    <link href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/4.6.1/css/bootstrap.min.css" rel="stylesheet">
  </head>
  <body>
    <!-- <h3>自定义模板</h3> -->
    <!-- <button class="btn btn-success">bootstrap</button> -->
    <div id="root"></div>
  </body>
</html>